How to Choose the Right Fish for Your Aquarium

How to Choose the Right Fish for Your Aquarium

Picking the right fish isn’t just about what looks good. It's about building a peaceful, healthy, and thriving tank. Consider the following when choosing livestock for your aquarium:

🐠 Research Fish Species

Start by learning the adult size, natural behavior, preferred water parameters (temperature, pH, hardness), and care level of each species. Don’t buy fish on impulse — plan your stock list based on your tank’s long-term needs.

📏 Tank Size & Setup

Always match your fish choices to the size and type of tank you have. Some fish need open swimming space, while others prefer plants or caves. Overstocking leads to stress, aggression, and poor water quality. Bigger fish = more space, more filtration.

🤝 Compatibility

Some fish are peaceful community dwellers. Others are aggressive, territorial, or even predatory. Research compatibility by temperament and bio-type. Avoid combining species with vastly different needs (e.g. hard vs soft water fish).

👥 Schooling & Social Behavior

Many fish are schooling species that must be kept in groups of 5–6 or more to thrive (e.g. tetras, rasboras, corydoras). Keeping them alone causes stress and shortens lifespan. Always research group size recommendations.

🚫 Avoid These Mistakes

  • Mixing aggressive and peaceful species
  • Adding fish to an uncycled tank
  • Ignoring adult size (some "small" fish grow over 12")
  • Buying incompatible fish because they "look cool"

Need help choosing fish for your setup? Reach out to us or visit our Tropical Fish Guide for beginner-friendly picks and tank builder tips.


Beginner-Friendly Freshwater Fish Chart

Fish Temperament Min Tank Size Care Level Notes
Platy Peaceful 10 gal Easy Hardy, active, good in groups
Guppy Peaceful 5 gal Easy Livebearer, fast breeder, colorful
Corydoras Catfish Peaceful 15 gal Easy Great bottom-cleaners, school in 4–6+
Zebra Danio Active, Peaceful 10 gal Very Easy Tolerates wide range, best in schools
Neon Tetra Peaceful 10 gal Easy Sensitive to poor water, school of 6+
Cherry Barb Peaceful 15 gal Moderate Colorful, less nippy than other barbs
Mollies Peaceful / Semi-Aggressive 20 gal Easy Prefer harder water, livebearers
Bristlenose Pleco Peaceful 30 gal Moderate Great algae eater, stays small

These fish are excellent for new hobbyists because they’re hardy, peaceful, and adapt well to most freshwater setups. Remember to always cycle your tank before adding fish, and avoid overstocking.